Emperor Taizong of Song (20 November 939 – 8 May 997), personal name Zhao Jiong, was the second emperor of the Song dynasty in China. He reigned from 976 to his death in 997. He was a younger brother of his predecessor, Emperor Taizu. His personal name was originally Zhao Kuangyi but he changed it to Zhao Guangyi in 960 and then finally to Zhao Jiong in 977.

Emperor Taizong succeeded the throne in 976 after the death of his elder brother, Emperor Taizu, who was 49 and had no recorded illness. It is rather unusual in Chinese history for a brother rather than the son to succeed the throne, so the event fueled popular belief that foul play was involved.

According to official history, Empress Dowager Du before her death in 961 asked the 34-year-old Emperor Taizu to promise that his brother will succeed him so as to ensure the continuation of the Song dynasty. She reportedly asked Emperor Taizu, "Do you know why you came to power? It was because Later Zhou had a seven-year-old emperor!" The so-called "Golden Shelf Promise" (金匱誓書) was also allegedly recorded and sealed, by secretary Zhao Pu and reopened after Emperor Taizong's succession to prove the latter's legitimacy.

Emperor Taizu's eldest son, Zhao Dezhao, was already 25 years old in 976, certainly old enough to handle an emperor's duties. Also suspicious is that Zhao Pu, banished in 973 by Emperor Taizu for allegations of corruption, returned to the capital in 976 and was made the chancellor in 977.

Wen Ying, a Buddhist monk who lived in the era of Emperor Taizong's grandson, Emperor Renzong, wrote an account about the last night of Emperor Taizu.[4] According to this account, he was dining and drinking with Emperor Taizong, then still the "Prince of Kaifeng", beside some candles. Palace eunuchs and maids standing in a distance saw that Emperor Taizong's shadow on the window moved a lot and appeared antsy. It was getting late and several inches of snow have fallen on the inside of the hall. Then they heard an axe chopping the snow, with Emperor Taizu saying, "Do it right! Do it right!" Soon enough Emperor Taizu was heard snoring. Several hours later, he was pronounced dead by his brother, who spent the night in his palace. This legend has been referred to as "sound of the axe in the shadow of the flickering candle" and proved to be popular to this day.[5]

Modern historians were unable to find any concrete evidence suggesting murder; however they generally accept that the "Golden Shelf Promise" as fraud fabricated by Emperor Taizong and Zhao Pu.

Also worth mentioning is the suicide of Zhao Dezhao, Emperor Taizu's eldest son, three years after his father's death. During Emperor Taizong's first campaign against the Khitan-led Liao dynasty, Zhao Dezhao was leading an army when rumours spread that Emperor Taizong had disappeared, and that Zhao Dezhao should be the new emperor.[6] Upon hearing that, Emperor Taizong did not award the troops when they returned. When Zhao Dezhao asked him, Emperor Taizong barked back, "You do that when you become the new emperor!" According to this account, Zhao Dezhao immediately went to his palace and killed himself.

Emperor Taizu's second son, Zhao Defang, died in 981 from an unidentified illness. Just 22, he was unusually young. During the same year, Emperors Taizong and Taizu's younger brother, Zhao Tingmei (previously known as Zhao Guangmei and Zhao Kuangmei), was also stripped of his title "Prince of Qi" and sent to the Western Capital. He died three years later. Moreover, when Emperor Taizu's widow Empress Song died, her body was not buried with her late husband and not given the recognition according to tradition.[7]

Having conquered Northern Han in 979, Emperor Taizong took advantage of the momentum and launched another military campaign against the Khitan-led Liao dynasty. In May 979, Emperor Taizong embarked on his campaign from Taiyuan and took Zhuo and Yi Prefectures easily. He besieged Yanjing (present-day Beijing) after the success. However, the siege failed when the Liao defending general Yelü Xuegu defended the fortress firmly.

Concurrently, Liao reinforcements led by Yelü Xiuge arrived from the Gaoliang River region, west of Yanjing. Emperor Taizong ordered his army to attack the reinforcements. Initially, he received reports that the Liao army was suffering heavy casualties. He ordered a full assault on the Liao army as he thought that the whole battle was under his control. Just then, Yelü Xiuge and Yelü Xiezhen's armies attacked from two sides. Yelü Xiuge concentrated on attacking Emperor Taizong's main camp. Emperor Taizong was shocked and evacuated from the battlefield. During the evacuation, the Song army was divided and obliterated by the Liao cavalry.

Amidst the onslaught, Emperor Taizong fled towards Yi Prefecture and arrived there safely with his generals protecting him. He sustained an injury from an arrow and was unable to ride on his horse and had to travel by carriage back to Ding Prefecture. Emperor Taizong ordered a retreat after that. The Song army was without a commander as Emperor Taizong was separated from his troops. The troops suggested that Emperor Taizu's eldest son, Zhao Dezhao (Emperor Taizong's nephew), be the new emperor. Emperor Taizong's suspicions were raised when he heard that and eventually he ordered Zhao Dezhao to commit suicide.

The Battle of Gaoliang River was significant as it was one of the major contributing factors to the Song dynasty's decision to adopt a defensive stance. The early Song army suffered its first major defeat in battle. Meanwhile, Emperor Taizong was also troubled by the possibility that Zhao Dezhao would launch a coup. After the battle, Emperor Taizong personally inspected and focused more on the development and strengthening of his military forces. He ignored his subjects' advice and regarded state affairs as of lower importance. He also limited the power and control that the imperial family and military officers had over the army.

Emperor Taizong remained in Bianjing and directed the war there without personally entering the battlefield. He split the army into three sections – East, Central and West. The East Army was led by Cao Bin, the Central Army by Tian Zhongjin and the West Army by Pan Mei and Yang Ye. All the three armies would attack Yanjing from three sides and capture it. The campaign was termed as the Yongxi Northern Campaign as it took place in the third year of the Yongxi era of Emperor Taizong's reign.

The three armies scored some victories initially but they became more divided later as they acted individually without cooperation. Cao Bin took the risk by attacking without the support of the other two armies. He succeeded in taking Zhuo Prefecture but the lack of food supplies forced him to retreat. As there was miscommunication between the three armies, the East Army attacked Zhuo Prefecture again. However, this time, Empress Dowager Xiao and Yelü Xiuge each led an army to support Zhuo Prefecture. The East Army was inflicted with a crushing defeat and almost completely destroyed.

Emperor Taizong was aware that the failure of the East Army would affect the entire campaign and he ordered a retreat. He ordered the East Army to return, the Central Army to guard Ding Prefecture and the West Army to guard four prefectures near the border. Following the defeat of the East Army, the Liao army led by Yelü Xiezhen attacked them as they retreated. The West Army led by Pan Mei met Yelü Xiezhen's army at Dai Prefecture and faced another defeat at the hands of the Liao army. The two commanders of the West Army started to argue about retreating. Yang Ye proposed that they should retreat since the East and Central Armies had already lost the advantage following their defeats. However, the other generals on Pan Mei's side began to doubt Yang's loyalty to Song as Yang Ye used to serve Northern Han. Yang Ye led an army to face the Liao troops but they were trapped and Yang committed suicide eventually. Pan Mei was supposed to arrive with reinforcements to support Yang but he failed to do so.

Emperor Taizong ordered another retreat following the Song armies' defeats by Yelü Xiuge and Yelü Xiezhen. The failure of the second campaign was attributed to the miscommunication between the three armies and their failures to operate together. Besides, Emperor Taizong had also restricted the decisions of his generals as he had arbitrarily planned the whole campaign against Liao and his generals had to adhere to his orders strictly. These failures led to internal rebellions which were crushed swiftly.

In 988, the Liao armies led by Empress Dowager Xiao attacked the Song border again. Emperor Taizong did not order a counter-attack and merely instructed the troops to defend firmly.

Emperor Taizong felt that he could not surpass his brother (Emperor Taizu) in terms of military conquests and achievements and decided to focus more on developing his dynasty internally and establish his legacy. He implemented a series of economic and literary reforms which were better than his brother's. He also initiated many construction projects and inducted new systems absent in Emperor Taizu's reign.

Emperor Taizong died in 997 after reigning for 21 years at the age of 57. He was succeeded by his third son, who became Emperor Zhenzong.